JUST IN: Boko Haram releases 21 abducted Chibok schoolgirls

Twenty-one of the 219 Chibok schoolgirls abducted by Boko Haram in Nigeria more than two years ago have been released into the custody of the government, a senior official saidThursday.

It was not immediately clear how the girls were rescued, but the Nigerian military has launched a large-scale operation in the Boko Haram stronghold Sambisa forest.

Boko Haram seized 276 students from the Government Girls Secondary School in Chibok on the night of April 14, 2014. Fifty-seven managed to escape in the immediate aftermath.

Until now, only one other girl had been rescued. Amina Ali, who was 17 at the time of her abduction, was discovered by civilian vigilantes in May and appeared to have given birth while in captivity.

A video released by Boko Haram in August purporting to show the rest of the kidnapped Chibok girls is only the second proof of life video obtained since their abduction.

In that video, a militant demanded the release of Boko Haram fighters in exchange for the girls. He also claimed that five of the Chibok girls were killed during Nigerian airstrikes on one of the group’s compounds.

The Chibok girls’ abduction sparked outrage worldwide launching the #BringBackOurGirls movement and bringing global attention to the Boko Haram insurgency, which has seen the repeated use kidnapping as a weapon in a war that has killed some 20,000 people since 2009.